This invention relates generally to a detent device, and more particularly to a detent device using a magnetic field.
Conventional detent devices typically rely on strictly mechanical means, such as a ball and socket. The ball is usually affixed to a moveable body, e.g. a lever, while the socket is located on a fixed body, or vice versa. When the moveable body rotates into an appropriate position, e.g., a detent position, the ball falls into the socket. The ball is typically spring loaded so as to remain in the socket until a force sufficient to compress the spring is exerted on the moveable body, freeing the moveable body from the detent position.
It is often desirable to have the lever be self-centering. Accordingly, various centering devices, such as springs, are often attached to the lever.
It is further often desirable to have the lever remain in the detent position until a certain event occurs, and then have the lever self-center. Unfortunately, this typically requires some type of mechanical device to xe2x80x9ckick outxe2x80x9d the lever from the detent position. These devices are often complex, expensive, and prone to malfunction.
The present invention provides apparatus and methods for restricting movement of a device. The detent device includes a housing, and a magnetic device, the magnetic device exerting a magnetic force and including a body and one of a recess defined therein and a protrusion. A magnetic body is located at least partially within the housing and is biased towards the magnetic device as a function of the magnetic force. The magnetic body includes a magnetic mass and the other of the recess defined therein and the protrusion, the other of the protrusion and the recess receiving the one of the protrusion and the recess of the magnetic device when the magnetic body is in a first predetermined position relative to the magnetic device. The magnetic mass of the magnetic body is spaced a first distance from the body of the magnetic device when the magnetic body is in the first predetermined position, and the magnetic mass of the magnetic body is spaced a second predetermined distance from the body of the magnetic device by the protrusion on the one of the magnetic device and the magnetic body when the magnetic body is in a second predetermined position relative to the magnetic device.